Why this cocktail shaker earns its place
A Boston is the shaker bar staff reach for when the list is long. It seals by pressure rather than by a screw thread or a fitted cap, so it goes together with a tap of the heel of the hand and comes apart with a strike in the same place. There is no cap to lose across a shift, no gasket to perish and no threaded lid to cross-thread when someone is working fast in the dark. The base is where the drink is actually made: ice in, liquid in, seal, shake, break the seal, pour. This one is supplied as that tin on its own.
Capacity is what separates a shaker that works from one that fights you, and 79 cl is a working figure rather than a serving figure. A shaken drink is chilled and diluted by ice moving through liquid, and ice only moves if there is air above it. Fill a tin to the rim and the contents sit still, the shake goes quiet and the drink comes out warm and under-diluted. At 79 cl there is room for a double serve, a full charge of cubed ice and the air space above them, so the shake stays loud and the dilution lands where it should.
Stainless steel is doing two jobs here. It pulls heat out of the drink quickly and frosts on the outside as it does, which gives the bartender a visible read on when a drink is cold enough without opening it. And a bare steel tin has nothing on it to break — it gets dropped on a bar mat, stacked wet, knocked against a tap arm and pushed through the glasswasher with everything else, and it comes out the far side ready to use. The silver finish keeps it presentable on a station the customer can see.
